The dimensions of an iPhone are x – 2 and x + 3. If the area of an iPhone is 14 square inches, find the dimensions of the iPhone

Mathematics

1 answer:

QveST [7]2 years ago

3 0

Answer:

The dimensions of the iphone are 2 inches by 7 inches.

Step-by-step explanation:

Given that,

The dimensions of an iPhone are x – 2 and x + 3.

The area of an iphone is 14 sq inches

We need to find the dimensions of the iPhone. It is in the shape of a rectangle. Its area is given by :

$A=l\times b\\\\(x-2)(x+3)=14\\\\x^2-2x+3x-6=14\\\\x^2+x-6-14=0\\\\x^2+x-20=0\\\\x^2+5x-4x-20=0\\\\x(x+5)-4(x+5)=0\\\\(x-4)(x+5)=0\\\\x=4\ and\ x=-5$

Neglecting negative value

First dimension = (x-2) = (4-2) = 2 inches

Other dimension = (x+3) = (4+3) = 7 inches

Hence, the dimensions of the iphone are 2 inches by 7 inches.

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Step-by-step explanation:

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We solve with a calculator $\frac{ln2}{25} =r\\0.0277=r$

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We repeat the step above substituting A=5,000,000, $A_0$ =50, and r=0.02777. Then solve for t.

$5000000=50e^{0.0277t}\\\frac{5000000}{50} =e^{0.0277t}\\100000=e^{0.0277t}\\ln100000=lne^{0.0277t}\\ln100000=0.02777t(lne)\\\frac{ln100000}{0.0277} =t$